Use of bubble load to interpret particle transport across the pulp-froth interface in a flotation cell

This work demonstrates the use of bubble loads to understand the transport of particles across the pulp-froth interface in a flotation cell processing an Upper Group 2 chromitite seam (UG2) ore. Bubble loads were measured on the first primary cleaner cell of an operating flotation plant using a bubble load meter with a 20mm riser diameter. A bubble load value of 10.58grams/liter was obtained. The bubble load data was used to understand, entrainment and dropback of chromite as a function of particle size. By defining terms such as froth flow number and net dropback, it was found that chromite (known to be non-floatable) was also recovered through true flotation. The entrainment of chromite was found to be predominantly in -25 μm size while +25 μm size particles were found to be floatable and highly susceptible to dropping back. Net-dropback of chromite particles was found to increase with a decrease in chromite particle size contrary to expectation. An overall froth flow number of 69% was obtained